les araignées bavardes

[Elendil]

Et tu as bien raison ! On sait que les Trolls de Pierre parlaient le westron, il n'est pas surprenant qu'ils aient conservé un objet enchanté qui s'exprime dans la même langue. En revanche, Tolkien met l'accent sur l'étrangeté du parler des araignées : on peut supposer qu'il ne s'agit pas du parler commun :

Standing behind a tree he watched a group of them for some time, and then in the silence and stillness of the wood he realised that these loathsome creatures were speaking one to another. Their voices were a sort of thin creaking and hissing, but he could make out many of the words that they said.

On constate d'ailleurs que Bilbo ne comprend pas le parler des Wargs quand ceux-ci entourent les arbres où les Nains se sont réfugiés. Il est notable qu'à ce moment, Bilbo ne porte pas l'Anneau au doigt :

These they guarded too, while all the rest (hundreds and hundreds it seemed) went and sat in a great circle in the glade; and in the middle of the circle was a great grey wolf. He spoke to them in the dreadful language of the Wargs. Gandalf understood it. Bilbo did not, but it sounded terrible to him, and as if all their talk was about cruel and wicked things, as it was.